Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae

Abstract

In the presented study a hyperspectral imager (400-700 nm) mounted on a stereo-microscope was used to separate differences in in vivo optical signatures identifying different pigment groups of bloom-forming phytoplankton and macroalgae by comparing spectral absorption, transmittance, and reflectance from 400-700 nm. The results show that the hyperspectral imager could be used to detect spectral characteristics on the microm level to calibrate, validate, identify, and separate objects with differences in color (optical fingerprinting). This information can be used for pigment group specific taxonomy (bio-optical taxonomy), eco-physiological information (e.g., health status), monitoring, and mapping applications.

Resolving Mixed Algal Species in Hyperspectral Images

“…The data is scaled between 0 and 1 for the wavelengths between 400 and 690 nm. This wavelength range captures the main absorption peaks observed at the spectral dips in the spectra that were also identified by Volent et al [14]. …”

“…Investigation of algal signatures using remote hyperspectral imaging has been reported by multiple research groups [12,14–18]. Craig et al applied hyperspectral remote sensing for the assessment of harmful algal blooms in reflectance mode for the detection of Karenia brevis [16].…”

“…[30,31]. In a laboratory setting, Volent et al used a hyperspectral imager attached to a microscope to measure the spectral response of algae in transmittance and reflectance modes [14]. The purpose of this group's study was to separate bloom-forming algae, such as phytoplankton and macroalgae, based on the acquired spectral response that captured pigment information.…”

A fish-eye view of cuttlefish camouflage usingin situspectrometry

“…We and others (McFarland & Munz, ; Endler, ; Cuthill et al ., ; Marshall, 2000b; Marshall et al ., 2003a, b; Hochberg et al ., ; Stuart‐Fox, Whiting & Moussalli, ; Mäthger et al ., ; Stuart‐Fox, Moussalli & Whiting, ; Dalton et al ., ) have used the best‐available spectrometers of various configurations in the field, and many investigators acknowledge the limitations of point‐by‐point sampling that hand‐held spectrometry imposes; yet, these studies provide a useful way forward and await technology development (e.g. hyperspectral imaging) to improve such visual studies (Cronin, Chiao & Ruderman, ; Vora et al ., ; Wachtler, Lee & Sejnowski, ; Nascimento, Ferreira & Foster, ; Párraga, Troscianko & Tolhurst, ; Long & Purves, ; Volent, Johnsen & Sigernes, ).…”

Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties

“…The UHI was used as a custom-made push-broom scanner (along track scanner) positioned with the image slit perpendicular to the moving direction according to Volent et al (2007Volent et al ( , 2009.…”